Female rats showed a uniform age-dependent decline in mitochondrial oxygen consumption across both ventricles (p<0.05), whereas respiratory states in male rats remained relatively stable.
Age-dependent decline in cardiac mitochondrial oxygen consumption exhibits significant sex differences, with a uniform decline observed only in female rats.
p-value: p=<0.05
Abstract Background and aims Mitochondria are considered central regulators of the aging process. Previous studies on the impact of age on mitochondrial oxygen consumption focused solely on skeletal muscle and male gender. So far, the exact impact of age on mitochondrial oxygen consumption in different gender in the heart is unknown. Thus, the aim of the present study was to evaluate mitochondrial oxygen consumption in the left and right ventricle of both gender in a preclinical ageing rat model. Methods Mitochondrial respiration of homogenized left and right heart ventricle of aging male and female Fischer 344 rats at the ages of 6, 12 and 24 months was determined using high-resolution respirometry (oxygraphs O2k, Oroboros, Austria). Here, different complexes of the mitochondrial respiratory chain were evaluated including PFAO, which equals the state of oxidative phosphorylation following injection of malate, palmitoyl-L-carnitine, ADP, and cytochrome c; and Complex IV (CIV), which equals the state of oxidative phosphorylation after complex III inhibition and addition of TMPD with ascorbate and sodium azide. Results Oxygen consumption rates were lower in the right compared to the left ventricles of both sexes. Significant gender-related differences were observed in PFAO and CIV in both ventricles of 12-month-old rats with lower oxygen consumption rates in female rats. In the heart of male rats, respiratory states remained relatively stable over analysed age categories with few exceptions of lower mitochondrial oxygen consumption at the age of 24 months. In comparison, female rats showed an uniformly decline in PFAO and CIV respiratory states in both ventricles at the analysed ages (p 0.05). Conclusion The results of our study indicate that the concept of a general pattern of age-dependent decline in mitochondrial oxygen consumption could be misleading. Male and female rats showed comparable rates of mitochondrial respiration across different age groups. However, only female rats were noticed to have a uniformly decline across both ventricles and different mitochondrial respiratory chain complexes.Oxygen consumption of both ventricles
Lerchner et al. (Sat,) conducted a other in Ageing. Ageing vs. Male vs female and different age groups was evaluated on Mitochondrial oxygen consumption (PFAO and CIV) in the left and right ventricle (p=<0.05). Female rats showed a uniform age-dependent decline in mitochondrial oxygen consumption across both ventricles (p<0.05), whereas respiratory states in male rats remained relatively stable.